Plastics Analysis

Plastics can present a very difficult challenge to the analyst. The plastic may contain a variety of additives, including other polymers, which are used to enhance the properties of the plastic compound. For example, plasticisers, inorganic fillers, antidegradants, fire retardants, and specialist additives such as antistatic agents and cross-linkers. It is unlikely that more than 90-95% of a complex formulation can be determined by analysis alone. Compounds may contain over 10 different ingredients, some present at very low levels. It is evident that a good plastics analyst must have a working knowledge of plastics technology to succeed.

Plastics analysis is used for a variety of purposes such as quality control, reverse engineering (deformulation) and to determine causes of failure.

A wide variety of techniques can be used to discover different facts about a plastic compound. For example, the elemental analysis may be required, or an instrumental method to determine the material's resistance to oxidation.

This review outlines each technique used in plastics analysis and then illustrates which methods are applied to obtain a particular result or piece of compositional information. For example, polymer and filler identification, molecular weight determination, antidegradant quantification and surface analysis study methods are all included.

The review also includes useful sections on specific areas, such as tests for plastics in contact with food, analysis of plastic laminates and fibres, and stabilisers in PVC

This text is a good introduction to a very complex subject area and will enable the reader to understand the basic concepts of plastics analysis.

Around 400 abstracts from the Polymer Library database accompany this review, to facilitate further reading. These include core original references together with abstracts from some of the latest papers on plastics analysis. These give examples of applications of the different techniques and some new developments.

Dr. Martin Forrest has worked in the Analysis Section at Rapra for over fourteen years. He is currently Principal Consultant Analyst, a position he has held for the past four years. He has experience in the analysis of a wide variety of polymers and polymer products using a range of techniques. He is one of the principal contacts at Rapra for projects involving plastics analysis.

Rapra has been serving the polymer community for over 80 years and was formerly known as the Rubber and Plastics Research Association of Great Britain. Rapra provides comprehensive analytical services to industry, research organisations and individuals using spectroscopic (FT-IR, infrared microspectroscopy, UV/vis spectroscopy),chromatographic (LC-MS, HPLC, GPC including triple detection, GC, GC-MS), thermal (DSC, TGA, DMTA, thermal diffusivity) and a range of wet chemical and other general and specialist techniques.